Now I know why Jaqen H'ghar speaks in his way. 'The boy' could also be translated to 'a boy', since there's no articles in High Valyrian. That explains the whole 'a girl' and 'a man'.
How do you tell whether the girl is plural or not? I can't figure it out :(
When in the accusative form (the object of the sentence), "Riñī" with a long ī is plural, while "Riñe" is singular.
In the nominative (the subect), "Riñi" with a short i is plural, while "Riña" is singular.
Vali riñī majaqis, couldn't that be, the men praise the girl, or, the men and the girl praise?